Joon-ho used to work in the army as a Company Commander of the anti-terrorism task force. He graduated and was an excellent student at the most prestigious military academy in Korea, where he earned a reputation for his strategic mind and unwavering integrity, As a leader, he and his teammates have successfully completed assigned tasks. Joon-ho is therefore admired and respected by many people, becoming a role model for his subordinates to follow. But Joon-ho's life suddenly changed completely when his entire family was murdered by a serial killer. The moment Joon-ho witnessed the murderer reenact his crime after being arrested by the police, he felt like he was crazy and immediately wanted to rush in to kill him, but was stopped by the police.Mentally depressed and always living in hatred, haunted by the unjust death of his entire family, Joon decided to leave the army and planned to take revenge, But ironically, the murderer who murdered his family that year committed suicide in prison, a death so peaceful, Joon-ho couldn't help but feel angry on behalf of his dead relatives, and he realized he had no reason to continue living, Joon-ho decided to commit suicide but failed when he was stopped by a strange man, The man told him about the injustice of justice and society's wrong tolerance for criminals, the man who wished Joon-ho to continue living to join the revenge association, Help the victims of injustice and take revenge on their behalf. Joon-ho eventually decides to join the man's association. He becomes a luxury taxi driver for Rainbow taxi company. This is not just an ordinary taxi company, but it provides revenge services on behalf of vulnerable people according to their requests. This company's work will of course be investigated by the police and prosecution. Between those who believe revenge is the embodiment of justice and those who pursue outlaws, Joon-ho will search for the true meaning of justice. And you are also one of the people who joined the revenge association.